High potential measuring transformer



April 12 1932. R

F. FISCHER HIGH POTENTIAL MEASURING TRANSFORMER Filed March 25, 1930 fiy/ v R r 692 5 Sheets-Sheet l April 1932- F. FISCHER 1,853,764

HIGH POTENTIAL MEASURING TRANSFORMER Filed March 25, 1930 3 Sheets-Sheet 2 T\ 1- 2/ *OL'OL' 1'00 45 g mi m l 22 g m i I 1 l l April 12, 1932.

F. FISCHER 1,853,764

HIGH POTENTIAL MEASURING TRANSFORMER Filed March 25, 1950 Alllllmnlllll mmnmmm 3 Sheets-Sheet 3 Patented Apr. 12, 1932 UNITED STATES FRANZ FISCHER, F DRESDEN, GERMANY,

ASSIGNOR TO KOCH & STI-RZEL AKTIEN- GESELLSCHAFT, OF DRLSDEN, GERMANY, A CORPGRATEON GIE GERMANY HIGH POTENTIAL MEASURING TRANSFORMER Application filed March 25, 1930, Serial No. 438,880, and in Germany March 27, 1929.

Choking coils or transformers for high potentials are already known in which the high potential winding and the iron core are subdivided into several parts, the separate part windings being connected in series and the part cores being insulated from earth and connected with the centre of the part winding subdivided in the vertical limb of the rectangular core. This connection does not need to be metallically conducting but can be which runs through the high potential winding and stresses the insulation of the wires thereof, consequently corresponds only to the harmless partial potential distributed on the part coil. By means of such a subdivision of the potential. drop, a better distribution of the potential is attained, in which the local stresses of the insulation become smaller. The building of the condensers of all systems as cylinder condensers arranged concen trically to each other is also already known.

The fitting of a magnetizing or shifting winding short-circuited on itself on to the ends or limbs of a column-shaped or rectangular iron core, carrying the two windings, and for the purpose of obtaining like potential stages the linking of all the ends of the elements connected in series by equalizing or overcoupling windings, electroanagnetically, is also known. These circuits of the socalled cascade transformers are shown in the Siemens-zeitschrift, of 1928, page 681, Figure 1.

An arrangement for reducing the potential difl'erence between the two windings of a high potential transformer has also been made known, in which the windings of the high potential transformer and of the auxiliary transformer are arranged on a common iron core insulated from earth and in which the secondary winding is carried out in two or more cylinder or layer windings, well separated from each other, and connected in series, the magnetizing winding (shittin winding) being so arranged close to one end of the coil system, that the potentials are approximately equal. Here, the pri mary coil is arranged above the secondary coil, so that both are also concentric to the shifting coil. This construction permits of a very wide build of the primary coil, a firm G6 coupling, a large energy transmission.

The object of the invention relates to trans formers, in particular measuring trans formers for high potential, consisting of separate systems connected in cascade with primary windings and shifting and ove coupling windings connected in series.

It is proposed, according to the invention, to arrange, with such transformers, all windings concentric to each other, and to separate 7% them by conductive and slit cylinders lying between them and connected with the ends of the primary winding arranged in layers, in order to thereby obtain a capacity coupling through all of the windings between them- .75

ture such as takes place with single layer windings between the first winding having the full potential, and the iron core, is avoided. Furthermore, by means 01" the conductive cylinders a static enclosing of all the layers of the primary winding is attained. 9G

The over-coupling windings placed round the primary winding and the secondary winding can also now be connected directly to these cylinders, so that they are coupled, in

the sense of the invention, capacitatively with the primary winding. With the part of the primary winding connected directly to the high potential, the first layer must be made as entry winding with enlarged conductive area since it is separated from the other layers by a conductive cylinder connected with the end of the entry layer and the commencement of the layer of the winding lying thereunder, and extending over the whole length of the layer. Here, the first layer forms one coating, and the cylinder the other coating, of an entry condenser which is connected in parallel to the first layer acting as entry choking coil, of the primary winding.

The conductive slit cylinders can not only be used as condenser plates, but may also at the same time serve as a winding, viz:--by connecting the winding layer above it to one of its ends, and the connection of the wind ing layer below it to its other end. Here, the winding layer may rest directly on the cylinder, or be separated therefrom. The conductive cylinders may be constructed as solid or grid shaped slotted metal cylinders, or as conductive rings, rods, or the like, arranged cylindrically and are open at their ends to permit of a free passage of air.

In the drawings there is shown an example of construction according to the invention in which Figs. 1 and 3 represent known circuit diagrams of cascade potential transformers.

Figs. 2 and 4 are diagrams showing theoretically the arrangement of the separate transformer systems according to the invent-ion.

Figs. 5 and 6 show, respectively, in transverse and longitudinal, vertical, section a constructional form of insulated housing within which the transformer system is mounted.

According to Figure 1, the upper end of the primary winding 11 is connected to the line 12 which carries the high potential to be measured. The primary winding 11 at its lower end is connected to the upper end of the next primary winding 14. Opposite these two windings 11 and 14 are placed the shifting windings 15 and 16 arranged on the iron core 13. The second transformer system lying thereunder is connected through overcoupling windings 17, 18 with the system above it, through two lines 19, 20. The line 19 here serves at the same time to connect 5": the primary windin 14 with the first primary winding 21 of the other system, as well as with the one end of the over-coupling windings 17, 18. On the iron core 22 of this second system are also placed, in addition to the shifting windings 23, 24, the second pri- These windings shown by the circuit diagram are, according to the invention, arranged as shown in Figures 2 and 4. First, the shifting windings 15 and 16 are fitted on the horizontally situated limb of the iron core 13, and their left-hand ends are connected at the points 29 with the core, their righthand ends being connected together by a line 30. Around these are placed two slit metal cylinders 31, 32, to each of which one end of the respective primary windings 11 and 14 is connected, the cylinders being also connected at the points 29 with the iron core. The primary windings 11 and 14 are wound in layers, and are arranged together with the cylinders 31,32, concentrically about the shifting windings 15 and 16. The uppermost layer 33 of the primary winding 11 is separated by the slit metal cylinder 34 from the other layers and connected electrically with one end of the winding and represents at the same time an entrance choking coil. It is situated on the metal cylinder 34 and is onclosed by the turned up edges thereof. Arranged on the uppermost layer of the primary winding 14 is fitted a slit metal cylinder 35 with turned up edges, to which the other end of the primary winding 14 is connected. Around this metal cylinder 35 is placed the over-coupling winding 17.

The same arrangement is carried out with the second system. Here, also, the horizontally situated limbs of the iron core 22 are again surrounded by the shifting windings 23 and 24, which are surrounded by slit metal cylinders 36, 37. On these are arranged the primary windings 21, 25. On the end layers of these windings are again fitted slit metal cylinders 38, 39. Between the metal cylinders 36, 38 and 37, 39, are connected the primary windings 21, 25. On the metal cylinder 38 is situated the over-coupling winding 18, and on the metal cylinder 39 the secondary winding 26, to which the measuring instrument 27 is connected. The end of the high potential winding 25 is connected with the metal cylinder 39 and through this with earth.

Thus, if an excess potential Wave occurs in the line 12, it will not be earthed directly through the primary windings of the transformers as in the known arrangements, but through the capacities 40, 41, 42, 43, 44, and 46 formed by the various windings and interposed cylinders. In this way injuries to the windings of the system are prevented.

The symbolical circuit diagrams given to the right of Figures 2 and 4, shown the capacities 40, 41, 42, 43, 44. 45, 46 and 47 existing between the ad acent windings and cylinders. '4

Here, the capacities 41, 42, 45 and 46 are again subdivided according to the number of the existing layers. The capacities existing be tween cylinders and windings are here the largest.

The individual systems 48, 49 consisting of the windings and the iron cores are secured, by means of extensions or lugs 51 formed on each of the systems and arranged substantially in the horizontal axis thereof to four in- I sulating rods 50. The lower ends of the rods are fastened. in the base armature About the frame thus formed there is placed a cylindrical insulating casing 53 formed in one piece, a cover or lid being placed over the upper end of said casing and to which the upper extremities of the rods 50 are secured. The stationary main column thus formed is then filled with oil and closed by means of a radiation cap 55.

lVhat I claim and desire to secure by Letters Patent of the United States is 1. In a high potential measuring transformer comprising individual systems con nected in cascade, and each including an iron core having a plurality of limbs, a shifting winding arranged on each limb of the iron core of each system, the shifting windings of each. system being connected in series and their free ends connected to the core, a primary winding arranged in layers concentrically about each shifting winding, the inner end of each primary winding being connected with the core, and an over-coupling vinding layer concentrically arranged about said primary winding, all of said windings associated with each of the limbs of the core being separated by means of conductive slit cylinders connected with the inner and outer ends of the primary windings to produce capacity coupling efiects throughout said windings.

2. In a high potential measuring transformer comprising individual systems con nected in cascade, and each including an iron core having a plurality of limbs, a shifting winding arranged on each limb of the iron core of each system, the shifting windings of each system being connected in series and their free ends connected to the core, a primary winding arranged in layers concentrically about each shifting winding, the in ner end of each primary winding being connected with the core, and an over-coupling winding layer concentrically arranged about said primary winding, the over-coupling winding of the first system being connected to high potential and forming the entrance layer, a conductive slit cylinder being arranged between the primary and overcoupling windings and extending over the full length of said primary winding, the cylinder being connected to the free end of the over-coupling winding and the outer end of the primary winding to produce a capacity coupling between said windings.

3. In a high potential measuring transformer comprising individual systems connected in cascade, and each including an iron core having a plurality of limbs, a shifting winding arranged on each limb of the iron core of each system, the shifting winding of each system being connected in series and their free ends connected to the core, a primary winding arranged in layers concentrically about each shifting winding, the inner end of each primary winding being connected with the core, and an over-coupling winding layer concentrically arranged about said primary winding, all of said windings associated with each of the limbs of the core being separated by means of conductive slit cylinders each connected with one end of each of the windings separated thereby, and forming one turn of said windings.

FRANZ FISCHER. 

